This invention relates generally to medical devices, and more particularly to a device for collecting cells at least from around the outer opening of the cervix of a human or veterinary patient, and preferably for collecting both cells from the lining within the cervix and cells around the outer opening of the cervix of a human or veterinary patient.
It has become virtually axiomatic that the best time to treat diseases such as cancer is when they are in their earliest phases. By necessity, the early treatment of cancer requires that it be detected early. A variety of known techniques for detecting cervical cancer entails the scraping or sampling of tissue from the uterine or endocervical canal, and from around the outer opening of the uterus (the cervical os). Tissues so obtained can be subjected to cytopathic or other examinations, perhaps the most common method of examination being the Pap (Papanicolaou) smear.
The known devices for exfoliating and collecting exocervical and endocervical tissue vary widely in complexity and utility. The most simple is a cotton swab introduced into the uterine canal. Wet spatulas have also been used to sample the exocervix and the uterine canal. Tissue samples have been aspirated through plastic or glass pipettes. Full dilation and curettage of the uterine canal has been employed, as have microcurettes. Brushes have been adapted to either exfoliate or collect endometrial tissue, but generally these have not been adapted to adequately perform both functions simultaneously. Generally, when the brush bristles are of a suitable length or stiff enough to exfoliate tissue well, they collect the exfoliated tissue poorly; and when the bristles are of a suitable length or flexible enough to collect tissue well, they fail to exfoliate sufficient tissue, or a sufficiently uniform sample of tissue.
One exception is the uterine endometrial tissue sample brush disclosed in U.S. Pat. No. 5,713,369 (Liang-Che Tao and John A. Maksem, Feb. 3, 1998). That brush, sold by COOK OB/GYN(copyright), simultaneously performs both of these functions quite well, and includes a generally cylindrical arrangement of bristles. Another brush incorporating a generally cylindrical arrangement of bristles is sold by COOK OB/GYN(copyright) under the name DETECT(copyright) Cytology Brush. This brush includes a polystyrene handle which carries the bristles on it, and which is scored to permit a portion of the handle carrying the bristles to be snapped off and used in conjunction with popular STD (sexually transmitted disease) test kits. The use of each of these brushes is intentionally limited to endocervical sampling, however, and these brushes are not intended to additionally sample exocervical tissues.
A diagnostic device for obtaining cytological samples from both the exocervix and the endocervix is disclosed in U.S. Pat. No. 3,626,470 (H. J. Antonides et al., Dec. 7, 1971). The device of that patent comprises an elongated handle which carries on it a foamed or spongelike pledget molded on a platform member. The pledget is impregnated with a critical amount of a proteolytic enzyme which acts upon mucus encountered at or retrieved from sites of cellular sampling, thereby avoiding interference with the subsequent analysis of the collected materials. The pledget includes a nose portion surrounding a stem extending upwardly from the platform member. The pledget preferably comprises a silastic RTV (room temperature vulcanizing) foam, for example, a mixture of dimethyl polysiloxane fluid polymers and inert diatomaceous earth fillers. Silicone rubbers, polyurethanes and polyether urethanes and the like are also asserted to be useful. The pore size for a foamed silicone rubber ranges from 130 to 546 microns; more particularly, the mean and standard deviation are about 336.2 xc2x198.5 microns. The apparent specific gravity is in the range of from 0.177 to 0.292, and more particularly, a mean value and standard deviation of 0.223xc2x10.028. Unfortunately, the disclosed variety of composition, pore size and specific gravity may not yield the best collection of cells, considering in combination the pliability of the foam (that is, the ability of the foam to take the shape of the internal and external surfaces of the cervix during sampling), the relative abrasiveness of the foam (increasing the number of cells which are scraped from the cervix) and whether the foam is open or closed cell (the former enhancing the retention and/or collection of the abraded cells).
U.S. Pat. No. 4,754,764 (I. D. Bayne, Jul. 5, 1988) similarly discloses a cervical cytology device which can include a disc for collecting exocervical cells, carried on a hollow shaft in which is telescopically received an endocervical brush for collecting cells. The disc and brush are preferably bristled, although urethane and polyurethane are suggested as materials for collecting cells. No specific physical arrangement of such other materials is disclosed, however.
The other conventional devices and techniques for sampling uterine endometrial tissue mentioned above have suffered their own drawbacks. Some sampling instrument diameters are uncomfortably large when inserted into the uterine canal, and their use can be sufficiently painful to the patient to require a general anesthetic. Some devices have undesirably low rates of successful insertion, while the use of others leads to unacceptably high rates of complications. Some devices have relatively poor yields (that is, inadequate sample sizes) when compared to conventional dilation and curettage. Full dilation and curettage, of course, entails its own trauma and disadvantages, including the infliction of open wounds requiring further post-procedural treatment. Many devices fail to obtain a large enough sample of tissue to ensure that localized abnormalities are detected.
It would be highly desirable to have a device which safely collects both exocervical and endocervical cells in relatively good patient comfort. It would also be highly desirable to have such a device which was simpler in construction than prior devices, and which did not include a relatively large plurality of individual bristles. It would further be desirable to have such a device in which the collecting portion or portions were sufficiently pliable to take on the shape of both the internal and external cervical surfaces being sampled. It would also be desirable to have such a device which was further adapted for use with other surgical devices, for example, for use with endoscopes, optic fibers, sensors, guide wires and other endocervical sample brushes.
The foregoing problems are solved and a technical advance is achieved in an illustrative medical device particularly adapted for abrading and collecting an acceptably large number of cells from at least the external surface of the cervix, and preferably from both the internal and external surfaces of the cervix. In one principal embodiment, the device of the present invention differs from prior devices for sampling cervical cells in that it employs a pair of foam portions each particularly suited for adequately sampling a different cervical surface.
More particularly, in this embodiment, the device of the present invention includes an elongate foam portion for sampling cells from the internal surface of the cervix, and a disk-like foam portion for sampling cells from the external surface of the cervix. The elongate foam portion and the disk-like foam portion can be carried on opposite ends of an elongate handle, or can be unitarily formed as a single foam portion carried by an end of the elongate handle. In either case, the elongate foam portion and the disk-like foam portion comprise an open cell, reticulated foam, preferably a foam as described in more detail below. The use of an open cell, reticulated foam permits the device of the present invention to enjoy superior sampling over prior cervical cell sampling devices, whether sampling only exocervical cells, or sampling both endocervical and exocervical cells.
In a second principal embodiment, the device of the present invention includes an open-celled, reticulate foam portion carried on the distal end of a hollow tube. The tube includes at least one lumen defined therein, which is dimensioned to receive one or more insertable structures or objects therein or therethrough. The insertable structure(s) or object(s) can be a guide wire, an endoscope, an optical fiber or a sensor. Preferably, the insertable structure or object is an endocervical brush having a plurality of bristles carried on an elongate brush handle. During introduction into a patient, the endocervical brush is preferably slidably received in the lumen of the hollow tube in a position such that the bristles of the endocervical brush are not exposed, but are instead contained within the tube lumen. Once the foam portion is adjacent the uterus, the endocervical brush is extended into the cervix, and rotated to obtain a sample of the endocervical cells.
In this embodiment, the device of the present invention can comprise not only the hollow tube and the open-celled, reticulate foam portion carried on it, but can further comprise the insertable structure(s) or object(s) with regard to which the lumen of the hollow tube is dimensioned.
Thus, in a first aspect, the present invention is directed to a medical device for collecting both endocervical cells and exocervical cells from a human or veterinary patient, comprising: an elongate handle having a first handle end and a second handle end opposite the first handle end; an elongate foam portion carried by one of the first handle end and the second handle end; and a disk-like foam portion carried by one of the first handle end and the second handle end; wherein the elongate foam portion and the disk-like foam portion comprise an open cell, reticulated foam and are sufficiently pliant to take the shape of the internal and external surfaces of the cervix when pressed by the handle against the internal and external surfaces of the cervix, respectively, and are sufficiently abrasive to scrape an acceptably large number of cells from the internal and external surfaces of the cervix when moved while being pressed by the handle against the internal and external surfaces of the cervix, respectively.
The elongate foam portion and the disk-like foam portion can be positioned on opposite ends of the handle, or can be unitarily formed as a single foam portion carried by one end of the handle, for example, the first handle end. Preferably, the elongate foam portion and the disk-like foam portion possess a relatively large mean pore diameter, on the order of or greater than about 1 mm. More preferably, the open cell, reticulated foam comprised by the elongate foam portion and the disk-like foam portion is a particular polyester polyurethane foam described in more detail below. The disk-like foam portion can be either a convex foam portion having a rounded or frustoconical surface opposite the handle, or a generally flat disk foam portion having a flat surface opposite the handle. The handle preferably includes at least one score permitting the handle to be separated manually at the at least one score. The at least one score is spaced from the elongate foam portion or the disk-like foam portion about 3 cm to about 5 cm.
The elongate foam portion preferably comprises a cylindrical body and a rounded end on the cylindrical body, and is about 0.6 cm in diameter. The disk-like foam portion is preferably about 1.9 cm to about 2.5 cm in diameter. Foam preferably extends about 1 mm beyond the handle end or tip on which the elongate foam portion and/or the disk-like foam portion is carried.
The handle can further comprise a tip carried by one of the first handle end and the second handle end, for example, the first handle end. The tip is of a size which is appropriate to assist dilation of the cervical os and then to provide subsequent support of the elongate foam portion during sampling, and can generally be about 7 French (2.3 mm) in diameter. The tip can include a bulbous head. At least the elongate foam portion is positioned about and is connected throughout its length to the tip. More preferably, the handle includes a hollow tube, and the device further comprises at least one base plate connected to one of the first handle end and the second handle end of the handle. At least one of the elongate foam portion and the disk-like foam portion is carried on the at least one base plate.
In a second aspect, the present invention is directed to a medical device for collecting both endocervical cells and exocervical cells from a human or veterinary patient, comprising: an elongate handle having a first handle end, a second handle end opposite the first handle end and a tip carried by the first handle end, the tip being generally about 7 French (2.3 mm) in diameter; a first base plate connected to the first handle end and a second base plate connected to the second handle end, the tip being carried on the first base plate; an elongate foam portion about 0.6 cm in diameter carried on the first base plate, comprising a cylindrical body and a rounded end on the cylindrical body, the elongate foam portion being positioned about and connected throughout its length to the tip; and a disk-like foam portion carried on the second base plate, the disk-like foam portion being about 1.9 cm to about 2.5 cm in diameter and including a rounded surface opposite the handle; wherein the elongate foam portion and the disk-like foam portion comprise an open cell, reticulated foam and are sufficiently pliant to take the shape of the internal and external surfaces of the cervix when pressed by the handle against the internal and external surfaces of the cervix, respectively, and are sufficiently abrasive to scrape an acceptably large number of cells from the internal and external surfaces of the cervix when moved while being pressed by the handle against the internal and external surfaces of the cervix, respectively; wherein the elongate foam portion and the disk-like foam portion possess a relatively large mean pore diameter; wherein the handle comprises a hollow tube having a first tube end to which the first base plate is connected, and a second tube end opposite the first tube end to which the second base plate is connected; and wherein the handle includes a pair of scores spaced one each about 3 cm to about 5 cm from the elongate foam portion and the second convex foam portion, the pair of scores permitting the handle to be separated manually at the pair of scores.
In a third aspect, the present invention is directed to a medical device for collecting both endocervical cells and exocervical cells from a human or veterinary patient, comprising: an elongate handle having a first handle end and a tip carried by the first handle end, the tip being generally about 7 French (2.3 mm) in diameter; a first base plate connected to the first handle end, the tip being carried on the first base plate; and a unitarily formed single foam portion carried by the first handle end on the first base plate, the single foam portion having an elongate foam portion about 0.60 cm in diameter and comprising a cylindrical body and a rounded end on the cylindrical body, and the single foam portion further having a disk-like foam portion positioned between the handle and the elongate foam portion, the disk-like foam portion being about 1.90 cm to about 2.00 cm in diameter and having a frustoconical surface opposite the handle; wherein the single foam portion is positioned about and connected throughout its length to the tip of the handle, comprises an open cell, reticulated foam and is sufficiently pliant to take the shape of the internal and external surfaces of the cervix when pressed by the handle against the internal and external surfaces of the cervix and is sufficiently abrasive to scrape an acceptably large number of cells from the internal and external surfaces of the cervix when moved while being pressed by the handle against the internal and external surfaces of the cervix, and possesses a relatively large mean pore diameter; wherein the handle comprises a hollow tube having a first tube end to which the first base plate is connected; and wherein the handle includes a score spaced about 3 cm to about 5 cm from the single foam portion which permits the handle to be separated manually at the score.
The foregoing aspects are all related to one principal embodiment of the present invention. Other aspects of the invention are related to another principal embodiment of the present invention. Accordingly, in another aspect, the present invention is directed to a medical device for collecting at least exocervical cells from a human or veterinary patient, comprising: an elongate handle comprising a hollow tube having a distal tip and a proximal end spaced from the distal tip, and at least one lumen defined therein, extending from the proximal end and to the distal tip; and at least one foam portion carried by the hollow tube and positioned about the distal tip of the hollow tube, the at least one foam portion comprising an open cell, reticulated foam which is sufficiently pliant to take the shape of at least the external surface of the cervix when pressed by the elongate handle against at least the external surface of the cervix, and which is sufficiently abrasive to scrape an acceptably large number of cells from at least the external surface of the cervix when moved while being pressed by the elongate handle against at least the external surface of the cervix; wherein the at least one lumen is dimensioned to receive at least one insertable structure or object therein or therethrough.
Preferably, the at least one insertable structure or object which the at least one lumen is dimensioned to receive comprises an endocervical brush, a guide wire, an endoscope, an optical fiber and/or a sensor. Also preferably, the device of the present invention additionally comprises the at least one insertable structure or object.
In a related aspect, the present invention is directed to a medical device for collecting at least exocervical cells from a human or veterinary patient, comprising: an elongate handle comprising a hollow tube having a distal tip, a proximal end spaced from the distal tip, at least one base plate connected to the distal tip and at least one lumen defined in the hollow tube, extending from the proximal end and to the distal tip; at least one foam portion carried on the at least one base plate of the hollow tube and positioned about the distal tip of the hollow tube, the at least one foam portion comprising an open cell, reticulated foam which is sufficiently pliant to take the shape of at least the external surface of the cervix when pressed by the elongate handle against at least the external surface of the cervix, and which is sufficiently abrasive to scrape an acceptably large number of cells from at least the external surface of the cervix when moved while being pressed by the elongate handle against at least the external surface of the cervix; and an endocervical brush; wherein the at least one lumen is dimensioned to receive the endocervical brush therein or therethrough; wherein the endocervical brush comprises a brush handle carrying a plurality of bristles thereon, and a round ball tip opposite the brush handle; wherein the at least one foam portion comprises a disk-like foam portion and an elongate foam portion unitarily formed with the disk-like foam portion, and possesses a relatively large mean pore diameter, the elongate foam portion being about 0.6 cm in diameter and the disk-like foam portion being about 1.9 cm to about 2.5 cm in diameter; and wherein the open cell, reticulated foam which is comprised by the at least one foam portion is a polyester polyurethane foam.
In a final aspect, the present invention is directed to a medical device for collecting at least exocervical cells from a human or veterinary patient, comprising: an elongate handle comprising a hollow tube having a distal tip, a proximal end spaced from the distal tip, at least one base plate connected to the distal tip and at least one lumen defined in the hollow tube, extending from the proximal end and to the distal tip; at least one disk-shaped foam portion carried on the at least one base plate of the hollow tube and positioned about the distal tip of the hollow tube, the at least one foam portion being about 1.9 cm to about 2.5 cm in diameter and comprising an open cell, reticulated foam which is sufficiently pliant to take the shape of at least the external surface of the cervix when pressed by the elongate handle against at least the external surface of the cervix, and which is sufficiently abrasive to scrape an acceptably large number of cells from at least the external surface of the cervix when moved while being pressed by the elongate handle against at least the external surface of the cervix; and an endocervical brush; wherein the at least one lumen is dimensioned to receive the endocervical brush therein or therethrough; wherein the endocervical brush comprises a brush handle carrying a plurality of bristles thereon, and a round ball tip opposite the brush handle; and wherein the open cell, reticulated foam which is comprised by the at least one disk-shaped foam portion is a polyester polyurethane foam.
The medical device of the present invention possesses significant advantages over prior devices for collecting endocervical and/or exocervical cells. Because its foam portions have good pliability, good relative abrasiveness and are open cell and reticulated, the device of the present invention safely collects both exocervical and endocervical cells in relatively good patient comfort. It is simpler in construction and therefore may be less expensive to manufacture than prior devices, since it does not include a relatively large plurality of individual bristles and therefore avoids the manufacturing step of connecting such individual bristles.
The medical device of the present invention also preferably includes an arrangement comprising one or more cellular structures each with at least one outermost layer of open and absorbent cells. In the arrangement, each cellular structure is supported by handle means and each structure is sufficiently contoured and pliant to adapt to the shape of the internal and/or external surfaces of a cervix to thereby collect endocervical cells and/or exocervical cells. As has been indicated, the cellular or foam structures on each end of the device arrangement can be on a single handle, multiple separate handles, or separate handles with separate collection means on a given end.